Automatic tire loader/unloader for stacking/unstacking tires in a trailer

ABSTRACT

An automatic tire loader/unloader for stacking/unstacking tires in a trailer is disclosed. In one embodiment, a mobile base structure provides a support framework for a drive subassembly, conveyance subassembly, an industrial robot, a distance measurement subassembly, and a control subassembly. Under the operation of the control subassembly, tires advance through a powered transportation path to an industrial robot which places the tires within the trailer in a vertical stacking pattern or a rick-stacking pattern, for example. The control subassembly coordinates the selective articulated movement of the industrial robot and the activation of the drive subassembly based upon the distance measurement subassembly detecting objects, including tires, within a detection space, dimensions of the trailer provided to the control subassembly, and dimensions of the tires provided to the control subassembly.

PRIORITY STATEMENT & CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/156,399 entitled “Automatic Tire Loader/Unloader forStacking/Unstacking Tires in a Trailer” filed on Jan. 15, 2014 in thename of Tim Criswell, now U.S. Pat. No. 9,440,349 issued on Sep. 13,2016; which claims priority from U.S. Patent Application No. 61/752,714entitled “Automatic Tire Loader/Unloader for Stacking/Unstacking Tiresin a Trailer” and filed on Jan. 15, 2013, in the name of Tim Criswell,all of which are hereby incorporated by reference for all purposes.

TECHNICAL FIELD OF THE INVENTION

This invention relates, in general, to a machine for handling productsand, more particularly, to a system and method for automated truckloading and unloading which employ an automatic tire loader/unloaderdesigned to stack tires within a trailer or remove tires from a trailer.

BACKGROUND OF THE INVENTION

Loading docks and loading bays are commonly found in large commercialand industrial buildings and provide arrival and departure points forlarge shipments brought to or taken away by trucks and vans. By way ofexample, a truck may back into a loading bay such that the bumpers ofthe loading bay contact the bumpers on the trailer and a gap is createdbetween the loading bay and the truck. A dock leveler or dock platebridges the gap between the truck and a warehouse to provide a fixed andsubstantially level surface. Power moving equipment, such as forkliftsor conveyor belts, is then utilized to transport the cargo from thewarehouse to the truck. Human labor is then employed to stack the cargoin the truck. This is particularly true of the stacking and unstackingof tires during the respective loading and unloading of the truck. Thesesystems are designed to maximize the amount the cargo loaded whileminimizing the use of human labor to both protect and extend the life ofthe workforce. A need still exists, however, for improved truck loadingsystems that further reduce the use of human labor when stacking andunstacking tires as part of loading and unloading a truck.

SUMMARY OF THE INVENTION

It would be advantageous to achieve a system and method for automatedstacking and unstacking of tires that would enable a truck to be fullyloaded and unloaded using minimal or no human labor, thereby minimizingthe time to load/unload the truck and the need for human capital. Itwould also be desirable to enable a robotic solution that would addressthis problem by stacking and unstacking tires using a rick-rack pattern,which is optimal for tire loading/unloading. To better address one ormore of these concerns, an automatic tire loader/unloader forstacking/unstacking tires in a trailer is disclosed. In one embodiment,a mobile base structure provides a support framework for a drivesubassembly, conveyance subassembly, an industrial robot, a distancemeasurement subassembly such as a three dimensional camera system, and acontrol subassembly. Under the operation of the control subassembly,tires advance through a powered transportation path to an industrialrobot which places the tires within the trailer in a vertical stackingpattern or a rick-stacking pattern, for example. The control subassemblycoordinates the selective articulated movement of the industrial robotand the activation of the drive subassembly based upon the distancemeasurement subassembly detecting objects, including tires, within adetection space, dimensions of the trailer provided to the controlsubassembly, and dimensions of the tires provided to the controlsubassembly. These systems and methodologies utilizing the presentautomatic tire loader therefore maximize the amount the product andcargo loaded while minimizing the use of human labor to both protect andextend the life of the workforce. These and other aspects of theinvention will be apparent from and elucidated with reference to theembodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures in which correspondingnumerals in the different figures refer to corresponding parts and inwhich:

FIG. 1 is a side elevational view with partial cross-section of oneembodiment of an automatic tire loader/unloader positioning tires withina trailer of a truck;

FIG. 2A is a top plan view of the automatic tire loader illustrated inFIG. 1;

FIG. 2B is a side elevation view of the automatic tire loaderillustrated in FIG. 1;

FIG. 2C is a second side elevation view of the automatic tire loaderillustrated in FIG. 1;

FIG. 2D is a front elevation view of the automatic tire loaderillustrated in FIG. 1;

FIG. 2E is a rear elevation view of the automatic tire loaderillustrated in FIG. 1;

FIG. 2F is a front perspective view of the automatic tire loaderillustrated in FIG. 1;

FIG. 2G is a rear perspective view of the automatic tire loaderillustrated in FIG. 1;

FIG. 3A is a perspective view of a portion of the automatic tire loaderof FIG. 1 and in particular a detailed view of one embodiment of amobile base;

FIG. 3B is a second perspective view of the mobile base illustrated inFIG. 3A;

FIG. 4A is a perspective view of one embodiment of an end effector,which forms a portion of the automatic tire loader, being posited togrip a tire;

FIG. 4B is a side elevation view of the end effector in FIG. 4A;

FIG. 4C is a top plan view of the end effector in FIG. 4A;

FIG. 5A is a perspective view of one embodiment of an end effector,which forms a portion of the automatic tire loader, gripping a tire;

FIG. 5B is a side elevation view of the end effector in FIG. 5A;

FIG. 5C is a top plan view of the end effector in FIG. 5A;

FIGS. 6A through 6D are schematic diagrams of one operational embodimentof the automatic tire loader of FIG. 1 stacking tires in the trailer ofthe truck;

FIGS. 7A through 7D are schematic diagrams of one operational embodimentof the automatic tire loader of FIG. 1 unstacking tires in the trailerof the truck;

FIGS. 8A through 8D are top plan views of an operational embodimentcorresponding to FIGS. 6A through 6D;

FIGS. 9A through 9D are top plan views of an operational embodimentcorresponding to FIGS. 7A through 7D;

FIG. 10 is a schematic block diagram of one embodiment of the automatictire loader;

FIG. 11 is a schematic block diagram of one embodiment of the automatictire loader in additional detail;

FIG. 12 is a schematic diagram of one embodiment of a robot controllerwhich forms a portion of the automatic tire loader;

FIG. 13 is a schematic diagram of one embodiment of a distancemeasurement subassembly which forms a component of the automatic tireloader; and

FIG. 14 is a schematic diagram of another embodiment of a distancemeasurement subassembly which forms a component of the automatic tireloader.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts, whichcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention, and do not delimit the scope of the presentinvention.

Referring initially to FIG. 1, therein is depicted an automatic tireloader/unloader that is schematically illustrated and generallydesignated 10 and may be referred to as the automatic tire loader. Thisautomatic tire loader 10 is utilized in systems and methods forautomated truck loading. A tractor trailer, for example, 12 having anoperator cab 14 is towing a trailer 16, which may be an ocean freightcontainer, for example, having a front wall 18, two side walls 20A, 20B(best seen in FIGS. 6A through 6D, for example), a floor 22, a ceiling24, and a rear access opening 26 accessible due to an open door. Asalluded to, as used herein, trailer includes ocean freight containersand similar transport and logistic structures. A bumper 28 of thetrailer 16 is backed up to a loading bay 30 of loading dock 32 such thatthe bumper 28 touches a bumper 34 of the loading bay 30. A dock plate 36bridges the gap between the floor 22 and a deck 38 of the loading dock32.

As will be described in further detail hereinbelow, under thesupervision of the distance measurement subassembly that is a componentof the automatic tire loader 10, the automatic tire loader 10 maneuversand drives automatically into the trailer 16 to a position proximate tothe front wall 18. It should be appreciated that although an operator isnot depicted as operating the automatic tire loader 10, an operator mayinteract with the equipment, although unnecessary. The automatic tireloader 10 operates independently of an operator and an operator is onlynecessary for certain types of troubleshooting, maintenance, and thelike. A telescoping conveyor unit 42 is connected to the automatic tireloader 10. A stream of product 46, in the form standard tires 46A-46H,which may be of any dimension, radius, and/or tread, is being suppliedby the telescoping conveyor 42 which, in turn, loads the product 46 intothe trailer 16. In particular, the automatic tire loader 10 has alreadystacked tires 46F, 46G and others, 46H, for example, at the intersectionof the front wall 18 and the floor 22. The automatic tire loader 10alternates between loading the tires 46 and reversing to create morespace for the tires 46 between the front wall 18 and the automatic tireloader 10 until the trailer 16 is at least partially loaded of tires 46.

FIG. 2A through FIG. 2G and FIG. 3A through FIG. 3B depict the automatictire loader 10 in further detail. A mobile base 50 supports a drivesubassembly 52, a conveyance subassembly 54, an industrial robot 56, apositioning subassembly 58, a safety subsystem 60, and a controlsubassembly 62, which interconnects the drive subassembly 52, conveyancesubassembly 54, industrial robot 56, positioning subassembly 58, andsafety subsystem 60. The mobile base 50 includes a front end 64 and arear end 66 as well as sides 68, 70, a surface 72, and an undercarriage74.

The drive subassembly 52 is coupled to the undercarriage 74 of themobile base 50 to provide mobility. As will be discussed in furtherdetail hereinbelow, drive wheel assemblies 78, 80, are disposed on theundercarriage 74 proximate to the sides 70, 68 respectively. A universalwheel assembly 82 is disposed on the undercarriage 74 more proximate tothe rear end 66 and centered between the sides 68, 70, respectively. Incombination, wheel assemblies 78, 80, 82 provide forward and reversedrive and steering. Retractable stabilization assemblies 84, 86 are alsodisposed on the undercarriage 74 proximate to the intersection of theend 64 and side 68, the intersection of end 66 and the side 70,respectively. As alluded to, in a forward or reverse drive and steeringoperation, such as moving into or out of the trailer 16, drive wheelassemblies 78, 80 and the universal wheel assembly 82 are actuated andin contact with the deck 38 of the loading dock 32 while the retractablestabilization assemblies 84, 86 are withdrawn from contact with the deck38 in a position close to the undercarriage 74. On the other hand, whenthe automatic tire loader/unloader 10 is conducting a tire loading orunloading operation, such as during the use of the industrial robot 56,the retractable stabilization assemblies 84, 86 are positioned incontact with the deck 38 to anchor the automatic tire loader/unloader10.

The conveyance subassembly 54 is disposed on the surface 72 of themobile base 50 to provide a powered transportation path 88 operable formeasuring, separating, carrying, and stacking, as required by theapplication and job assignment of the automatic tire loader/unloader 10,tires from the rear end 66 to the front end 64 proximate to theindustrial robot 56. As shown, the powered transportation path 88includes a powered roller conveyor 90 having roller elements 92 whichdeliver the tires 46 to a landing platform 94 where manipulation by theindustrial robot 56 is initiated. It should be appreciated that althoughonly a single powered roller conveyor 90 is display, the poweredtransportation path 88 may include any combination and type ofconveyors, elevators, stackers, and bypasses and the particularcombination of components selected for the powered transportation path84 will depend upon the particular tires or other product andapplication of the automatic tire loader/unloader 10.

The conveyance subassembly 54 as well as the telescoping conveyor unit42 may also each be equipped with a series of end stop photo eyes toadjust the rate of automatic flow of product through the telescopingconveyor unit 42 and the conveyance subassembly 54. Such animplementation provides a steady and continuous flow of product,maintains proper tire or product separation, and prevents unnecessarygaps between the product and product backups and jams.

A telescoping conveyor interface 104 couples the roller conveyor 90 ofthe conveyance subassembly 54 to the telescoping conveyor unit 42 andthe rest of a pick belt system which may be at the warehouse associatedwith the loading dock 32. Auto-follow circuitry associated with thetelescoping interface 104 of the telescoping conveyor unit 42 and theconveyance subassembly 54 may utilize fiber optic sensors at the lastboom of the telescoping conveyor unit detect reflective tape at the edgeof the conveyance subassembly to cause the telescoping conveyor unit 42to extend and retract to maintain the proper position with respect tothe automatic tire loader/unloader 10. In another embodiment, thetelescoping conveyor unit 42 may be passive and other elements mayprovide the force required to extend or retract.

The industrial robot 56 is disposed at the front end 64 and adapted toprovide selective articulated movement of an end effector 130 betweenthe landing platform 94 of the powered transportation path 88 and areachable space 132 such that the industrial robot 56 is operable toplace the product 46 in the reachable space 132. The end effector 130includes a gripper arm 134 adapted for manipulating product withopposing grapplers 136A, 136B. It should be appreciated that any type ofend effector 130 may be employed the industrial robot and the choice ofend effector 130 will depend upon the product 46 and specific automatictire loader 10 application. By way of example, the gripper arm 134 withopposing grapplers 136A, 138B is preferred for loading tires 46A-46H. Itshould be understood, however, that the product 46 may be any type ofgood such as other non-tire objects requiring loading.

In one implementation, the industrial robot 56 includes seven segments130, 138, 140, 142, 144, 146, 148 joined by six joints 150, 152, 154,156, 158, 160 to furnish selective articulated movement having sixdegrees of freedom. More particularly, the referenced reachable space132, as best seen in FIGS. 2F and 2G, is defined by the movement of theindustrial robot 56 which provides rotation about six axes includingrotary movement of the entire industrial robot 56 about a primaryvertical axis; rotary movement of segment 146 having a tower structureabout horizontal axis to provide extension and retraction of the segment144 having a boom arm; rotary movement of the boom arm about thehorizontal axis to provide raising and lowering of the boom arm; andselective rotary movement about three wrist axes.

The positioning subassembly 58 is dispersed throughout the mobile base50. A distance measurement subassembly 170 disposed at the front end 64of the mobile base 50 measures distance and determines the presence ofobjects within a detection space 172 which is located in front of thefront end 64. In one embodiment, the detection space 172 and thereachable space 132 at least partially overlap. The distance measurementsubassembly 170 assists the automatic tire loader/unloader 10 withforward and reverse movement and the repositioning of the automatic tireloader 10 to create additional empty reachable space 132 for theplacement of the product 46. Further, the distance measurementsubassembly 170 assists with the coordination and operation of theindustrial robot 56. Distance and measurement information gathered bythe distance measurement subassembly 170 is provided to the controlsubassembly 62.

As will be discussed in further detail hereinbelow, the distancemeasurement subassembly 170 may be a laser range finding apparatusoperating on a time-of-flight measurement basis or principle, or athree-dimensional camera system, for example. It should be appreciated,however, that other types of distance measurements are within theteachings of the present invention. By way of example, and not by way oflimitation, the distance measurement subassembly may include a laserrange finding apparatuses, ultrasonic measurement apparatuses,inclinometers, camera systems, and combinations thereof. Similar todistance measurement subassembly 170, distance measurement subassemblies174, 176 are respectively disposed at the sides 68, 70 and, depending onthe application, may or may not required. The distance measurementsubassemblies 174, 176 each include detection spaces (not illustrated)to provide measurement and distance information to the controlsubassembly 62 during traverse movement operations of the automatic tireloader/unloader 10.

The safety subsystem 60 is distributed and mounted to the mobile base50. The safety subsystem 60 may include a light tower which provides aquick indication of the current status of the automatic tireloader/unloader 10 to an operator and a wireless operator alert system182 which contacts pagers or cellular devices of individuals through awireless network. Also a cage and railing may be included around theoperator platform 40 to provide additional safety to the operator.Emergency buttons may be located throughout the automatic tireloader/unloader 10 to provide for instant and immediate power down.Front safety bumpers or, alternatively, scanners 188 and rear safetyscanners 190 may be positioned at the front end 64 and the rear end 64to protect the automatic tire loader/unloader 10, people, and productduring a collision with an obstacle. Additionally, the front safetyscanners 188 and the rear safety scanners 190 may include detectors thatdetect the presence of an object and cause an automatic power downduring a collision. Side safety bumpers, although not illustrated, mayalso be utilized. It should be appreciated that other safety featuresmay be integrated into the automatic tire loader/unloader 10.

The control subassembly 62, which is also distributed and mounted to themobile base 50, may include control station having a user interfacedisposed at the side 70 near the rear of the mobile base 76. Asdiscussed, the drive subassembly 52, the conveyance subassembly 54, theindustrial robot 56, the positioning subassembly 58, and the safetysubassembly 60 are interconnected and in communication with the controlsubassembly 62 via a network of concealed and sheathed cables and wires.With this arrangement, the control subassembly 62 may coordinate themanual and automatic operation of the automatic tire loader/unloader 10.

A main frame 200 is constructed of welded steel tubing includes tubularsections 202, 204, 206, and 208 which provide a rectangular framework.The tubular sections 202-208 are supported by tubular sections 208, 210,214, 216, 218, and 220, which augment and further support therectangular framework. All mounting plates, such as mounting plates 222,224 and bolt holes necessary to hold the various components attached tothe mobile base 50 are included in the main frame 200. The large plates222, 224 hold, for example, the control station and the user interfacein position while providing counter weight for the automatic tireloader/unloader 10 as well as balance with respect to the industrialrobot 56 disposed proximate to the mounting plates 222, 224. Additionalcounter weight may be supplied by tractor weights mounted proximate tothe rear end 66, which also serve to add additional support andintegrity to the main frame 200.

Drive wheel assemblies 78, 80 include a pair of front drive wheels 252,250 disposed proximate to the front end 64 and, more particularly,proximate the intersection of tubular sections 208, 214 and tubularsections 204, 214, respectively. Respective AC motors 254, 256 withdouble reduction gearboxes 258, 260 supply power thereto. The AC motor254 with double reduction gearbox 258 is disposed adjacent to thetubular section 214 and the front drive wheel 250. Similarly, the ACmotor 256 with double reduction gearbox 260 is disposed adjacent to thetubular section 214 and the front drive wheel 252. The universal wheelassembly 82 includes a rear steering wheel 284 mounted to a frame 286disposed proximate to the rear end 66.

With reference to the operation of the drive subassembly 52 inconjunction with the mobile base 50, the drive wheel assemblies 78, 80and universal wheel assembly 82 provide mobility along the length of theautomatic tire loader 10. The AC motors 254, 256 with the respectivedouble reduction gearboxes 258, 260 drive the front drive wheels 250,252. In particular, each front drive wheel 250, 252 is independentlydriven to provide the ability to turn and to provide a pivoting drivemode. The universal wheel assembly 82 provides a rear steering wheel 284to provide enhanced steering capability for the automatic tire loader10. In addition to providing forward and reverse capability, the oneembodiment, the drive subassembly 52 may furnish a traverse drive systemproviding the capability to move the entire automatic tire loader 10perpendicular to a trailer or fixed object at the loading dock 32.

Referring now to FIGS. 4A through 4C and FIGS. 5A through 5C, wherein anend effector 130 having gripper arm 134 with opposing grapplers 136A,136B is depicted positioned to grip a tire 46 in FIGS. 4A through 4C andis actively gripping a tire in corresponding FIGS. 5A through 5C. Moreparticularly, the end effector 130 includes a support frame 300 forattachment to the industrial robot 56 and the support frame 300 includeshousings 302, 304 having guide tracks 306, 308 radially offset andspaced apart. Retaining elements 310, 312 are mounted to the supportframe 300 and include respective tire contacting surfaces 314, 316configured to contact the tire 46. Selectively moveable elements 318,320 are mounted on the respective guide tracks 306, 308 for transversemovement along the housings 302, 304 of the support frame and superposedextension and retraction thereabove to provide for the action of theopposing grapplers 136A, 136B. The selectively moveable elements 318,320 include deviated contact plates 322, 324 configured to contact thetire 46 at an inner radius. In operation, by extension and retraction ofthe opposing grapplers 136A, 136B the tire 46 may be gripped at theinner radius and released.

FIGS. 6A through 6D depict one operational embodiment of the automatictire loader 10 stacking tires 46A-46G in the trailer of the truck.Referring now to FIG. 6A, tires 46A-46G are positioned in an emptytrailer of the truck in a rick-rack stacking pattern by the automatictire loader/unloader 10. More specifically, the distance measurementsubassembly 170 continuously determines the position of the automatictire loader/unloader 10 within the trailer and the presence of objects,including tires 46, is known. When beginning a rick-rack pattern, theautomatic tire loader/unloader 10 identifies an empty tire skyline 330and chooses an active quadrant 332 to begin stacking operations. Asequential tire placement direction 334 is also identified such that theactive quadrant 332 advances horizontally across the trailer 16 of thetruck. Initially, within the active quadrant 332, a placement angle α isspecified for the placement of the first tire 46A. Thereafter, for tires46B-46G, placement angles α are determined and the automatic tireloader/unloader 10 with the use of the end effector 130 places the tires46B-46G, where as shown tire 46G is being placed.

With reference to FIG. 6B, with the first row of tires 46A-46G complete,the tire skyline 330 is identified and within the tire skyline 330 ahole and a bump of an adjacent tire pair is identified. For example,hole 336 and bump 338 of tires 46A, 46B is identified to determine tire46M should be placed adjacent to tire 46L and superposed on tires 46A,46B. With reference to FIG. 6C, this methodology continues with theskyline 330 and activity in quadrant 332, from which the sequentialplacement direction 334 will advance. The hole 336 is identified withtire 46M and the side wall 20B of the trailer serves as the bump forplacement of the tire 46N. The sequential tire placement continues untilthe trailer of the truck is filled as shown in FIG. 6D, with 3A tires,46A-46Z and 46AA-46MM.

FIGS. 7A through 7D depict one operational embodiment of the automatictire loader 10 unstacking tires in the trailer 16 of the truck. In FIG.7A, the unstacking methodology begins by the identification of the tireskyline 330 and the active quadrant 332 from which sequential tireremoval will advance as identified by number 340. Bump 338 and hole 336of the adjacent tire pair are identified and as shown in FIG. 7B, thetire 46MM is removed following the automatic tire loader/unloader 10providing the appropriately calculated instructions for removing tiresfrom the rick-rack pattern. This methodology continues in FIGS. 7C and7D, wherein upon reaching the bottom row, the automatic tireloader/unloader sequentially removes the last row of tires 46A-46G.

Referring now to FIGS. 8A through 8D, wherein one embodiment of anautomated tire loading system and methodology are illustrated for theautomatic tire loader/unloader 10 of the present invention. Initially,as shown in FIG. 8A, the trailer 16 is positioned under the power of thetractor trailer 12 at the loading bay 30 of the loading dock 32approximate to the deck 38 where the automatic tire loader/unloader 10is working. The trailer 16 is set-up, cleaned, and activated in a usualmanner. The dock plate 36 is deployed from the loading bay 30 into thetrailer 16 to provide a bridge. Thereafter, the trailer 16 is inspectedfor significant damage that may interfere with the automated loadingoperations of the automatic tire loader/unloader 10. Additionalinspection may include ensuring the trailer is reasonably centeredwithin the loading bay 30 and ensuring the deck 38 is clear of anyobstructions. At this time, by way of further safety measures, a kingpinlockout may be installed to prevent a driver from accidentally pullingout the trailer 16 from the loading bay 30 when the automatic tireloader/unloader 10 is operating within the trailer 16. The kingpinlockout or similar safety precautions protect both the operator 40 andthe equipment and ensures that the wheels of the trailer 16 are chockedand will not roll during the use of the automatic tire loader 10.

Continuing to refer to FIG. 8A, once the trailer 16 is positioned in theloading bay 30, the automatic tire loader/unloader 10 is moved in frontof the rear access opening 26 of the trailer 16. The automatic tireloader/unloader 10 utilizes either a manual or automatic reverse mode toassist the operator (whether on the automatic tire loader/unloader 10 orat a remote location) in backing the automatic tire loader/unloader 10up to the telescoping conveyer unit 42 in a position that is squarethereto. The conveyance subassembly 54 of the automatic tire loader 10is then coupled to the telescoping conveyor unit 42. At this time, asthe dock plate 36 has been positioned from the deck 38 to the trailer16, the automatic tire loader/unloader 10 may be advanced into theinterior of the trailer 16.

With reference to FIG. 7B, the automatic tire loader/unloader 10 hasadvanced forward into the trailer 16 and, in one embodiment, thepositioning subassembly 58 and, in particular, the distance measurementsubassembly 170 continuously determines the position of the automatictire loader/unloader 10 within the trailer 16. More specifically,several measurements are made. The position and angle of the automatictire loader/unloader 10 are measured with respect to the sidewalls 20A,20B and an interior width defined thereby. Also, measurements are madewith respect to a near wall within the trailer 16 and the floor 22. Thenear wall being the closer of the front wall 18 of the trailer or theedge formed by product 46, e.g. tires, positioned within the trailer 16.The angle relative to the floor 22 proximate to the automatic tireloader/unloader 10 is measured as the automatic tire loader/unloadertraverses the dock plate 36 and moves into the trailer 16. In oneembodiment, following successful traversal, the angle relative to thefloor 22 may be assumed to be constant.

In this way, as the automatic tire loader/unloader 10 moves, theposition of the automatic tire loader/unloader 10 relative to objects inits environment, including tires, is known and the automatic tire loader10 may adjust operation appropriately. Adjustments in operation mayinclude, but are not limited to, the operation of the industrial robot56, the operation of the conveyance subassembly 54, and the actuation ofthe drive subassembly 52. The position of the sidewalls 20A, 20B and thenear wall is utilized to determine the position of the automatic tireloader 10 along the length of the trailer 16, the position across thewidth of the trailer 16, and the automatic tire loader's angle relativeto the sidewalls 20A, 20B or yaw. The measurements also determine theposition of the automatic tire loader/unloader 10 relative to the floor22 of the trailer 16. To assist the automatic tire loader/unloader 10 indetermining position within the trailer 16, in one implementation, theautomatic tire loader/unloader 10 is programmed with the dimensions ofthe trailer 16.

Additionally, in one embodiment, the automatic tire loader/unloader 10is programmed with the reachable space 132 of the industrial robot 56.As illustrated, once the automatic tire loader/unloader is positionedproximate to the front wall 18 of the trailer 16 such that the placementof tires 46 against the front wall 18 of the trailer 16 is within thereachable space 132 of the industrial robot 56, the automatic tireloader/unloader 10 stops advancing. Continuing to refer to FIG. 8B,tires 46 are conveyed from the telescoping conveyor unit 42 to theconveyance subassembly 54 and this stream of tires 46 is presented tothe industrial robot 56. With selective articulated movement through thereachable space 132, the industrial robot 56 places the tires 46 withinthe trailer and sequentially loads the tires 46 according to a stackingroutine designed to optimize the use of available space within thetrailer 16. For example, the stacking routine may be the rick-rackstacking pattern presented in FIGS. 6A through 7D or vertically stackedtires.

In the illustrated embodiment, this stacking routine places product insequentially rick-rack stacked rows. By way of example, FIG. 8Billustrates a first rick-rack stacked row 344A being completed. Thisstacking routine or other alternative stacking routine may be optimizedfor the size of the end effector 130 of the industrial robot 56, thedimensions of the trailer 16, and the dimensions of the product 46.

As depicted in FIG. 8C, the automatic tire loader/unloader 10 hascompleted stacking multiple horizontal rows 344A-344D of tires 46. Theloading of the tires 46 by the industrial robot 56 is temporarilyinterrupted in response to the distance measurement subassembly 170detecting the presence of the tires 46 within the reachable space 132.Further, with this information being available to the controlsubassembly 62, a signal may be sent to the conveyance subassembly 54 toslow down or temporarily halt the powered transport of the product 46.

As a result of the completion of a row, such as rows 344A-344D, theautomatic tire loader/unloader 10 periodically reverses and repositionsto refresh the reachable space 132 such that the automatic tireloader/unloader 10 is positioned proximate to the wall of placed tires46 in order that the placement of additional tires 46 against the wallof placed tires 46 is within the reachable space 132 of the industrialrobot 56. During the repositioning of the automatic tire loader/unloader10, the telescoping conveyor unit 42 appropriately retracts, whilemaintaining contact with the conveyance subassembly 54, to accommodatethe new position of the automatic tire loader/unloader 10.

Referring to FIG. 8D, the iterative stacking operations andrepositioning of the automatic tire loader/unloader 10 described inFIGS. 8A through 8C continues and the trailer 16 is filled. With respectto FIG. 8D, the trailer 16 is completely filled with tires 46, includingrows 344A-344F, and the automatic tire loader 10 is reversed to aposition entirely on the deck 38. Thereafter, the trailer 16 filled withtires may leave the loading dock 32 and a fresh empty trailer may thenbe positioned at the loading bay 30 and loaded in the manner describedherein.

FIGS. 9A through 9D depict the iterative unstacking operations andrepositioning of the automatic tire loader/unloader 10. As shown, theautomatic tire loader/unloader 10 unstacks tires 46 from the filledtrailer having rows 344A-344I in a manner opposite to that described inFIGS. 8A through 8D until the trailer 16 is empty in FIG. 9D.

FIG. 10 depicts one embodiment of the automatic tire loader/unloader 10in which the automatic tire loader/unloader 10 is schematically depictedto include a computer-based architecture including a processor 350coupled to a bus 352 having transmitter/receiver circuitry 354, outputs356, inputs 358, memory 360, and storage 362 interconnected therewith.In one embodiment, the control assembly 192 includes the memory 360,which is accessible to the processor 350. The memory 360 includesprocessor-executable instructions that, when executed cause theprocessor 350 to execute instructions for stacking or unstacking tires46 or other objects. By way of example and not by way of limitation, theinstructions may be directed to stacking tires in a rick-rack orvertical pattern or unstacking tires from a rick-rack or verticalpattern. With respect to stacking tires in a rick-rack pattern, theinstructions may include specifying a search operation to identify atire skyline including an active quadrant, specifying a search operationto identify a hole and hump of an adjacent tire pair within the activequadrant, specifying a search operation to identify the sequential tireplacement direction, and the calculation of instructions for executing arick-rack stacking pattern of tires.

Other types of tire stacking/unstacking operations involve other typesof instructions. Removing tires, whether from a rick-rack or verticalstack, requires a search operation to identify the sequential tireremoval direction. Further, operations may specify instructions forexecuting a rick-rack unstacking pattern of tires, instructions forexecuting a vertical stacking pattern of tires, or instructions forexecuting a vertical unstacking pattern of tires, for example. It shouldbe appreciated that although a specific computer architecture isdepicted in FIG. 10, other architectures are within the teachingspresented herein.

FIG. 11 depicts one embodiment of the automatic tire loader/unloader 10and the control signals associated therewith, which may be deployedacross the computer architecture shown in FIG. 10, for example. Theillustrated components coordinate the various functions and operationsof the automatic tire loader/unloader 10. The user interface 194,operational environment database 370, programmable logic controller 372,robot controller 374, and distance measurement subassemblies 170, 174,176 are interconnected. The drive subassembly 52, conveyance subassembly54, as represented by control 376 for conveyors/elevators, and safetycontroller 378 are connected to the programmable logic controller 372.Finally, the industrial robot 56 is connected to the robot controller374. In one implementation, the user interface 194, operationalenvironment database 370, and programmable logic controller 372 are partof the control subassembly 62 and the robot controller 374 forms aportion of the industrial robot 56. The safety controller 358 isincluded in the safety subsystem 60 and provides operation to theaforementioned components of this subsystem.

The user interface 194 provides user control and interaction with theautomatic tire loader/unloader 10. The user interface 194 may utilizeicons in conjunction with labels and/or text to provide navigation and afull representation of the information and actions available to theoperator. In addition to loading operations, user interactions may berelated to maintenance, repair and other routine actions which keep theautomatic tire loader 10 in working order or prevent trouble fromarising.

The operational data environment database 370 includes data about thereachable space 132 of the industrial robot 56, stacking methodologydata, product information as well as information about the standardsizes of trailers. The product information may be stored in theoperational data environment database 350, gathered by the conveyancesubassembly 54 as previously discussed, or gained by a combinationthereof. By having the standard sizes of trailers pre-loaded, operatortime is saved from having to enter this data and performance of theautomatic tire loader/unloader 10 is improved with this additionalinformation. By way of example, Tables I & II present exemplary examplesof type of trailer data that the automatic tire loader/unloader 10 mayutilize in determining position and product placement.

TABLE I TRAILER DIMENSIONS Inside Inside Door Trailer Inside HeightHeight Opening Type Length Width Center Front Width 28′ 27′3″ 100″  109″107″ 93″  (8.5 m)  (8.3 m) (2.5 m) (2.8 m) (2.7 m) (2.4 m) High Cube 45′44′1½″ 93″ 109″ 106″ 87″ (13.7 m) (13.4 m) (2.4 m) (2.8 m) (2.7 m)   (2m) Wedge 48′ 47′3″ 99″ 110½″ 108½″ 93″ (14.6 m) (14.4 m) (2.5 m) (2.8 m)(2.8 m) (2.4 m) Wedge

TABLE II TRAILER DIMENSIONS CONTINUED Door Rear Trailer Opening FloorCubic Overall Overall Type Height Height Capacity Width Height 28′ 104″47½″ 2029 cft 102″ 13′6″  (8.5 m) (2.6 m) (1.2 m) (57.5 cm)  (2.6 m)(4.1 m) High Cube 45′ 105½″ 50″ 3083 cft  96″ 13′6″ (13.7 m) (2.7 m)(1.3 m)  (7.3 cm) (2.4 m) (4.1 m) Wedge 48′ 105″ 48½″ 3566 cft 102″13′6″ (14.6 m) (2.7 m) (1.2 m) (101 cm) (2.6 m) (4.1 m) Wedge

The programmable logic controller 372 coordinates overall operation andswitches between various modes of operation including manual andautomatic. The programmable logic controller 372 also provides for thehigh-level calculation and coordination required during automaticoperation for items such as the current loading/unloading quadrant andsteering angel calculations during automatic navigation.

The robot controller 374 controls the motions of the industrial robot 56through built in inputs and outputs wired through the industrial robot56 and the end effector 130. It should be appreciated that although aparticular architecture is presented for the control of the automatictire loader, other architectures are within the teachings of the presentinvention. By way of example, any combination of hardware, software, andfirmware may be employed. By way of further example, the distribution ofcontrol may differ from that presented herein.

In one operation embodiment, the programmable logic controller 372accesses the dimensions of the trailer 16 from the operationalenvironment database 372. The operator 40 has indicated through the userinterface 194 which type of trailer has arrived at the docking bay 30.Alternatively, the distance measurement subassembly 170 is operable todetect this information. The distance measurement subassembly, which mayinclude various components 170, 174, 176, relays distance and positiondata to the programmable logic controller 352 which uses thisinformation to send control signals to the robot controller 374, thedrive subassembly 52, the controller 372, and the safety controller 378.Additionally, the programmable logic controller 372 receives controlsignals, which are inputs into the behavior process, from each of thesecomponents. Constant updates and status information are provided to theoperator 40 by the programmable logic controller 352 through the userinterface 194.

FIG. 12 depicts one embodiment of the robot controller 372 which forms aportion of the automatic tire loader 10. The essence of the robotcontrol 372 is a robot system or control program 380, which controls theindustrial robot 56. The control program 380 can be operated by theoperator 40 by means of an operating service 362 in communication withthe user interface 194 and receives input data (as well as provideinstructions, as appropriate) from the operational environmentaldatabase 370, programmable logic controller 372, and distancemeasurement subassembly 170 by means of a driver 384. It should beappreciated, that the independence of the robot controller 374 may vary.In one implementation, the robot controller 374 may be under the controlof the programmable logic controller 374. In another implementation, asillustrated, the robot controller 374 is more autonomous and may includefeatures such as direct connection to the user interface 194.

According to one embodiment, between the driver 384 and the controlprogram 380 is provided an independent data processing layer in the formof a frame program 386, which controls the robot movements, and a unit388 for automated or event-controlled strategy or behavioral selectionon the basis of the states and signals which occur. User applicationprograms, event-controlled strategy selections and sensor programs inthe frame program 386 can be programmed by the operator 40 and directedby a robot program 390, which monitors the balance and implementation ofmanual and automatic control of the industrial robot 56.

FIG. 13 depicts one embodiment of a distance measurement subassembly,i.e., a laser measurement sensor 400. A staging circuit 402 causes apulsed laser 404 to transmit light pulses while causing the rotation ofa light deflecting device 406 via controller 408 which may be equippedwith a rotational means and a motor. The angular position of the lightdeflecting device 406 is continuously communicated to the stagingcircuit 402 by the controller 408. Light pulses are transmitted into thedetection space 172 via the transmitter lens and the mirrors associatedwith the light deflection device 406. More particularly, when the rotarymirror of the light deflection device 406 is driven by the controller408 to execute a continuous rotary movement, the staging circuit 402causes the pulsed laser 404 to transmit a light pulse. The light pulseis transmitted into the detection space 172 and is reflected from anobject, so that finely a received pulse enters into a photo receivingarrangement 410. In this manner the light reaches the photo receiverarrangement 410 after a light transit time t of 2d/c, where d is thespace in the object from the apparatus and c is the speed of light.

The time t between the transmission and reception of the light pulse ismeasured with the aid of a comparator 412 having time interval computerfunctionality. On transmitting the light pulse, a counter functionwithin the comparator 412 is triggered and is stopped again by the photoreceiver arrangement 410 via the comparator 412 on receiving the lightpulse from the detection space 172.

A corresponding electrical signal is formed and applied via comparator412 to a laser scanner controller 414, signal to noise processor 416 anda detector 418, which analyzes the signal for objects and in the instantexample determines that an object is present. The task of the signal tonoise processor 416 is to control the detection threshold independenceon the received noise level. This control ensures a constant false alarmrate with varying illumination situations and object reflection factors.The signal to noise processor 416 makes available this information tothe laser scanner controller 414. The laser scanner controller 414performs peak value calculations based on the data from the comparator412, the signal to noise processor 416, and the detector 418.

As the laser scanner controller 414 knows the instantaneous angularposition of the light pulses by way of communication with the stagingcircuit 402, the laser scanner controller 414 determines the location ofthe object and other navigational properties. The laser scannercontroller 414 is adapted to forward this information to othercomponents.

FIG. 14 is a schematic diagram of a distance measurement subassembly170, which is depicted as a three dimensional (3-D) measurement system450, which includes an illumination assembly 452 and an image capturesubassembly 454 that together utilize a laser and/or infrared-basedcamera application employing an adaptive depth principle. Theillumination assembly 452 includes a light source 456 and a transparency458, which may include a positive image on a transparent support with avarious sorts of fixed, uncorrelated patterns of spots, for example.

The light source 456 transilluminates transparency 458 with opticalradiation so as to project an image of the spot pattern that iscontained by the transparency onto object 46A, which is depicted as thetire, but may also include various environmental information about thestorage container. The image capture assembly 454 captures an image ofthe pattern that is projected by illumination assembly 452 onto tire46A. The image capture assembly 454 may include objective optics 464,which focus the image onto an image sensor 460. Typically, the imagesensor 460 includes a rectilinear array of detector elements 462, suchas a CCD or CMOS-based image sensor array.

As should be appreciated, although the illumination assembly and imagecapture assembly are shown as held in a fixed spatial relation, variousother positioning techniques may be employed to create a dynamicrelationship therebetween. Moreover, the three-dimensional x, y, z axismay be employed in this regard. To generate a 3D map of object or tire46A, including the environment, a processor, which may incorporated intoprocessor 350 or associated therewith, compares the group of spots ineach area of the captured image to the reference image in order to findthe most closely-matching group of spots in the reference image. Therelative shift between the matching groups of spots in the image givesthe appropriate x, y or Z direction shift of the area of the capturedimage relative to the reference image. The shift in the spot pattern maybe measured using image correlation or other image matching computationmethods that are known in the art. By way of example, the operationprinciple may include an infrared adaptive depth principle utilizinglaser or infrared cameras.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is, therefore, intended that the appended claimsencompass any such modifications or embodiments.

What is claimed is:
 1. An automatic tire loader/unloader forstacking/unstacking tires in a trailer, the automatic tireloader/unloader comprising: a base structure having first and secondends; an industrial robot disposed at the second end of the basestructure, the industrial robot providing selective articulated movementof an end effector between the powered transportation path and areachable space such that the industrial robot is operable to place thetires in the reachable space; a distance measurement subassemblydisposed at the second end, the distance measurement subassemblyconfigured to determine presence of objects within a detection space,wherein the detection space and the reachable space at least partiallyoverlap; a control subassembly mounted to the base structure, thecontrol subassembly being in communication with the industrial robot andthe distance measurement subassembly, the control subassemblycoordinating the selective articulated movement of the industrial robotbased upon the distance measurement subassembly detecting objects withinthe detection space; and the control assembly including a memoryaccessible to a processor, the memory including processor-executableinstructions that, when executed cause the processor to: specify asearch operation to identify a tire skyline including an activequadrant, specify a search operation to identify a hole and hump of anadjacent tire pair within the active quadrant, specify a searchoperation to identify the sequential tire placement direction, andcalculate instructions for executing a rick-rack stacking pattern oftires.
 2. The automatic tire loader/unloader as recited in claim 1,wherein the memory further comprises processor-executable instructionsthat, when executed cause the processor to: specify a search operationto identify a tire skyline including an active quadrant, specify asearch operation to identify a hole and hump of an adjacent tire pairwithin the active quadrant, specify a search operation to identify thesequential tire removal direction, and calculate instructions forexecuting a rick-rack unstacking pattern of tires.
 3. The automatic tireloader/unloader as recited in claim 1, wherein the memory furthercomprises processor-executable instructions that, when executed causethe processor to: specify a search operation to identify a tire skylineincluding an active quadrant, specify a search operation to identify thesequential tire placement direction, and calculate instructions forexecuting a vertical stacking pattern of tires.
 4. The automatic tireloader/unloader as recited in claim 1, wherein the memory furthercomprises processor-executable instructions that, when executed causethe processor to: specify a search operation to identify a tire skylineincluding an active quadrant, specify a search operation to identify thesequential tire removal direction, and calculate instructions forexecuting a vertical unstacking pattern of tires.
 5. The automatic tireloader/unloader as recited in claim 1, wherein the end effectorcomprises a gripper arm adapted for manipulating tires with opposinggrapplers.
 6. The automatic tire loader/unloader as recited in claim 1,wherein the end effector further comprises: a support frame forattachment to the industrial robot, the support frame including firstand second guide tracks radially offset and spaced apart; first andsecond fixed retaining elements mounted to the support frame, the firstand second fixed retaining elements having respective tire contactingsurfaces configured to contact a tire; and first and second selectivelymoveable elements mounted on the first and second guide tracks fortransverse movement along the support frame and superposed extension andretraction thereabove, each of the first and second selectively moveableelements including a deviated contact plate configured to contact thetires at an inner radius.
 7. The automatic tire loader/unloader asrecited in claim 1, further comprising a drive subassembly coupled tothe base structure, the drive subassembly including a plurality ofwheels for steering and driving the base structure, the plurality ofwheels including a pair of front drive wheels disposed proximate to thesecond end, the pair of front drive wheels being powered by respectiveAC motors with double reduction gearboxes.
 8. The automatic tireloader/unloader as recited in claim 1, further comprising a drivesubassembly coupled to the base structure, the drive subassemblyincluding a plurality of wheels for steering and driving the basestructure, the plurality of wheels including a rear drive wheel disposedproximate to the first end.
 9. The automatic tire loader/unloader asrecited in claim 1, further comprising a conveyance subassembly disposedon the base structure, the conveyance subassembly including a poweredtransportation path operable for transporting tires between the firstend and the second end, wherein the conveyance subassembly including aconveyor having a telescoping conveyor interface for coupling theautomatic tire loader to a telescoping conveyor unit.
 10. The automatictire loader/unloader as recited in claim 1, further comprising aconveyance subassembly disposed on the base structure, the conveyancesubassembly including a powered transportation path operable fortransporting tires between the first end and the second end, wherein theconveyance subassembly further comprises a powered roller conveyor. 11.The automatic tire loader/unloader as recited in claim 1, wherein thedistance measurement subassembly comprises a three dimensionalmeasurement system operating on an adaptive depth measurement principle.12. The automatic tire loader/unloader as recited in claim 1, whereinthe distance measurement subassembly comprises a device selected fromthe group consisting of laser range finding apparatuses, cameras,ultrasonic measurement apparatuses, inclinometers, and combinationsthereof.
 13. The automatic tire loader/unloader as recited in claim 1,wherein dimensions of the trailer are programmed into the controlsubassembly.
 14. The automatic tire loader/unloader as recited in claim1, wherein dimensions of the tires are programmed into the controlsubassembly.
 15. An automatic tire loader/unloader forstacking/unstacking tires in a trailer, the automatic tireloader/unloader comprising: a base structure having first and secondends; an industrial robot disposed at the second end of the basestructure, the industrial robot providing selective articulated movementof an end effector through a reachable space such that the industrialrobot is operable to place the tires in the reachable space; the endeffector including a pair of fixed retaining elements and acorresponding pair of selectively moveable elements configured to gripthe tires at an inner radius; means for determining presence of objectswithin a detection space, wherein the detection space and the reachablespace at least partially overlap; a control subassembly mounted to thebase structure, the control subassembly being in communication with theindustrial robot and the means for determining presence, the controlsubassembly coordinating the selective articulated movement of theindustrial robot based upon the distance measurement subassemblydetecting objects within the detection space; and the control assemblyincluding a memory accessible to a processor, the memory includingprocessor-executable instructions that, when executed cause theprocessor to execute a plurality of the following instructions: specifya search operation to identify a tire skyline including an activequadrant, specify a search operation to identify a hole and hump of anadjacent tire pair within the active quadrant, specify a searchoperation to identify the sequential tire placement direction, specify asearch operation to identify the sequential tire removal direction,calculate instructions for executing a rick-rack stacking pattern oftires, calculate instructions for executing a rick-rack unstackingpattern of tires, calculate instructions for executing a verticalstacking pattern of tires, and calculate instructions for executing avertical unstacking pattern of tires.
 16. An automatic tireloader/unloader for stacking/unstacking tires in a trailer, theautomatic tire loader/unloader comprising: a base structure having firstand second ends; an industrial robot disposed at the second end of thebase structure, the industrial robot providing selective articulatedmovement of an end effector between the powered transportation path anda reachable space such that the industrial robot is operable to placethe tires in the reachable space; a support frame for attachment to theindustrial robot, the support frame including first and second guidetracks radially offset and spaced apart; first and second fixedretaining elements mounted to the support frame, the first and secondfixed retaining elements having respective tire contacting surfacesconfigured to contact a tire; and first and second selectively moveableelements mounted on the first and second guide tracks for transversemovement along the support frame and superposed extension and retractionthereabove, each of the first and second selectively moveable elementsincluding a deviated contact plate configured to contact the tires at aninner radius; a distance measurement subassembly disposed at the secondend, the distance measurement subassembly configured to determinepresence of objects within a detection space, wherein the detectionspace and the reachable space at least partially overlap; a controlsubassembly mounted to the base structure, the control subassembly beingin communication with the industrial robot and the distance measurementsubassembly, the control subassembly coordinating the selectivearticulated movement of the industrial robot and based upon the distancemeasurement subassembly detecting objects within the detection space;and the control assembly including a memory accessible to a processor,the memory including processor-executable instructions that, whenexecuted cause the processor to: specify a search operation to identifya tire skyline including an active quadrant, specify a search operationto identify a hole and hump of an adjacent tire pair within the activequadrant, specify a search operation to identify the sequential tireplacement direction, and calculate instructions for executing arick-rack stacking pattern of tires.
 17. The automatic tireloader/unloader as recited in claim 16, wherein the distance measurementsubassembly comprises a device selected from the group consisting oflaser range finding apparatuses, ultrasonic measurement apparatuses,inclinometers, and combinations thereof.
 18. A method for stacking tireswithin a trailer parked at a loading bay, the method comprising:detecting the location of the automatic tire loader/unloader within thetrailer with a distance measurement subassembly disposed on a basestructure; presenting a stream of tires to an industrial robot disposedon the base structure, the industrial robot providing selectivearticulated movement through a reachable space such that the industrialrobot is operable to place the tires within the trailer; executing atthe automatic tire loader/unloader a rick-rack stacking routineincluding processor-executable instructions to: specify a searchoperation to identify to identify a tire skyline including an activequadrant, specify a search operation to identify a hole and hump of anadjacent tire pair within the active quadrant, specify a searchoperation to identify the sequential tire placement direction, andcalculate instructions for executing a rick-rack stacking pattern oftires; sequentially loading the tires within the trailer with theindustrial robot according to the rick-rack stacking routine designed tooptimize the use of available space within the trailer; and interruptingthe loading of tires in response to detection by the distancemeasurement subassembly presence of tires within the reachable space.19. The method as recited in claim 18, wherein executing at theautomatic tire loader/unloader a rick-rack stacking routine includingprocessor-executable instructions further comprises execution ofprocessor-executable instructions to: specify a search operation toidentify a hole and hump of an adjacent tire pair within the activequadrant, specify a search operation to identify the sequential tireremoval direction, and calculate instructions for executing a rick-rackunstacking pattern of tires.